1. Field of the Invention
The present invention relates to an impressed current cathodic protection system for a marine engine and to an electrode therefor. The cathodic protection system preferably provides a protective current flow through a coolant passage.
2. Description of the Related Art
A conventional outboard motor engine often uses sea water as cooling water and is equipped with a cathodic protection device for preventing electrolytic corrosion. Known cathodic protection devices include impressed current type devices having an electrode connected to a battery. The electrode is located upstream of the engine in a cooling water passage and provides a cathodic protection current into the cooling water. The electrode serves as an anode and the engine serves as a cathode. Although corrosion protection is provided near the electrode, this arrangement does not provide corrosion protection to areas in contact with a relatively thin cooling water passage inside the engine.
Cathodic protection devices employing an impressed current system are used for non-engine applications. An exemplary structure includes a linear cathodic protection electrode that passes through a water conduit or pipe. A cathodic protection current flows from the cathodic protection electrode to the wall of the conduit.
The cathodic protection electrode is formed by a strand of fine monofilament yarn wrapped a metal wire. Since the electrode is formed by winding a string around a metal wire, the linear cathodic protection electrode is costly to manufacture.